Rappstar wrote:
chicanery wrote:
dev, this is not correct.
There are two failure modes. One is the seat post slipping, which would be generally non-catastrophic.
The other failure is with the pivot on the beam. The difference between the Dimond design and the original Zipp is that the Zipp had both the pivot, AND an m5 bolt. Normally that bolt is not under much load, unless the pivot were to fail. Then it would be under an enormous load and would probably fail. Steel bolt into a steel cam/pivot system into a threaded steel shaft into aluminum epoxied into the frame.
If the Dimond pivot fails, the beam comes off. You will crash. If the carbon AT the pivot fails, the beam will come off, and you will crash. Since I was fixing a defect in the seat post area of my beam, I also added 3 layers of UD carbon to the pivot area on each side of my beam. It's not a terrible design, but Jordan is right that the tolerances must be extremely tight, and that Dimond's QC is not good enough in that respect.
Correct. This is my exact assertion. And one that I expressed to Dimond on multiple occasions well in advance in of making my statement here. And I have records of that.
The statement in bold there are a lot of if's. Could we not say the same about failure of any frame member on a conventional bike. If my head tube fails or fork fails, I crash. And so on.
The point here, is that it is just conjecture by Chicanery and Jordan that the pivot MIGHT fail. Did you do the destructive testing etc etc to determine that, or was it a random guess based on your engineering intuition. My engineering intuition at visual inspection suggests lots of products MIGHT fail, however, the engineers working at those companies have the design-test-validation-field testing and released products to the public based on much more thorough testing than us consumers. In this thread, Colin Laughery posted TJ's statement that Dimond has not had any field failures.
Where all all these Dimond field failures?
I get it that Jordan is an engineer but to my best knowledge his field of engineering is not designing bikes. Maybe Dimond cut some corners, maybe their testing is not up to others, or maybe their QA is bad or maybe none of that. But in spite of all of that their bikes can be safe for riding even if they creak or they MIGHT look like they could explode.
I like both Jordan and TJ and it is no secret that I have been a fan of what he is doing with his bikes. Early in this thread, I wished the thread would just go away and the gentleman would resolve the dispute offline from lawyers and the internet.
But I see zero proof so far that the bikes are unsafe so I am being the pain in the ass guy asking for the proof. Can they do better on attention to detail and finer craftmanship? Seems like after some growing pains a lot of owners are saying they are.